Centrifugal impeller for aircraft and other uses



Feb. 1, 1944. -r 2,340,427

CENTRIFUGAL IMPELLER FOR AIRCRAFT AND OTHER USES Filed June 26, 1942 3 Sheets-Sheet 1 68 arm 0.1 m,

Feb. 1, 1944. -r 2,340,427

CENTRIFUGAL IMPELLER FOR AIRCRAFT AND OTHER USES Filed June 26, ,1942

s Sheets-Sheet s gardless of the namic balance of the ically maintained, as hereinafter explained and Patented Feb. 1, 1944 CENTRIFUGAL IMPELLER FOR AIRCRAFT AND OTHER USES Hal-lie 0. Putt, Elkhart, Ind.

Application June 26, 1942, Serial No. 448,635

9 Claims. (01. 170-135) The object of myinvention is to provide a meth-' d and means of creating a greater thrust or,

traction effort by means of the developed vacuum and pressure effect, per unit of effective area and power input, than can be achieved with the conventional aircraft propeller, in a manner herein after fully explained.

A further object is to provide an aerial impeller, comprising a circular rotary air-foil, of strong and simple structure and capable of being driven.

at relatively high speeds, whereby a maximum' thrust effort is developed by a high velocity centrifugal displacement of air over said air-foil, at approximately right anglesto the axis of rotation.

It is also an object to provide an 1mpe1ler struc ture capable of being employed for both vertical and horizontal flight and thus eliminate the conventional aircraft wing structure and propeller.

A further object of the invention is to provide a method and means for the operation of my in' vention by centrifugal forces to effect vertical or forward thrust when rotating in one direction and a centripetal, or reverse action when rotating in a reverse direction.

It is also an ct to provide means whereby" the vertical and forward thrust will result, re-

to provide method and means whereby the dyimpeller may be automat described.

I attain these and other advantages of my invention by the structure illustrated in the accompanying drawings and herein described, in

which- Figure 1 is a plan view of the circular rotary air-foil impeller mounted in its driving houss;

Fig. 2 is a vertical sectional view of Fig.1 on,

a center line through Fig. 1;

Fig. 3 is a detail vertical sectional view of the circular rotary air-foil impeller head;

Fig. 4" is a detail vertical sectional view of the vacuum plate;

Fig. 5 is a detail vertical sectional view of the cone-shaped lower member;

Fig. 6 is a vertical sectional view of one form of rotary fan on the center line li6 of Fig. '1,

' showing the curved vanes formed integral with their base plate;

Fig. '7 is a top plan view of showing the curved fan vanes; p

. Fig. 8 is. a top plan view of'the rotary ,fan

the" rotary fan,

direction of impeller rotation; and

Referring to the drawings, I provide a circular formedair-foil head I, shaped approximately as shown in Figs. 2 and 3. On its top side and centrally located, is formed a circular depression or V concave area 8, in which the rotary fan, as shown in Figs. 7 or 8, is emplaced and rigidly attached thereto. A plurality of slots or ports l0 are equally disposed circumferentially in the air-foil head, as shown and their number should equal the number of vanes employed on the fan. Ports In function to create a vacuum between the inner walls of the head I and the vacuum plate 3 to increase the strength or stiffen these members against the action of centrifugal force on them by virtue of the vacuum pulling them toward each other. A centrally disposed clearance hole I l is provided to accommodate the upper end of the reduced shaft I2, as shown. The lower edge or rim of member I is slightly flanged as shown at 9, to form a seal with the outer flared edge l6 of the bell-shaped member 4, as shown at 9-16 of Fig. 2.

A suitably formed circular vacuum plate 3, as shown in Figs. 2 and 4,is provided with a plurality'of radially disposed ribs I3 and a central hole [4. The outer rim of this plate is'formed with the flange l5 to accurately fitthe internal curved wall of the air-foil head I just belowthe ports l0, as shown in Fig. 2.

A threaded nut 22 (see Fig. 2) is screwed tightly onthe threaded shaft l2 to a point justabove the transverse hole 20 drilled through said'shaft. Then the vacuum plate 3 and spacer 23, both of which have centrally located clearance holes, are

cular ribbed brace l1 and end plug l8 (Fig. 2), v

pressed or shrunk onto the reduced portions of the shaft as shown, and finished to fit snugly within the cone-shaped member 4, to which they should be welded or brazed and the plug l8 made fluid tight therewith. A hole 19 is drilled in the upper end of the threaded shaft l2 to commu- The upper bearing 2'! is now emplaced on the v I bearing hub 26, which is then assembledwithin the bearing housing 2, whereitisheld rigidly the jam-nut 28 which is locked in position by he screw 29, or by other suitable means. end of the impeller shaft lz isnow inserted into the bore of the hub 26 until thereperedmw er end of member 4 seats securedly and accurately in the tapered bore of said hub. The lower bearmg at is now'jeni ia'c d and the lock nut 13! tightened up securely, thus clamping bearing 30 m pmee and. drawing the lowe tap'ered'en'd of "member "4 tightly into its "seat in theupp'erend oi the hub 26, as shown. The beveled pinion gear '32 "is now 'emplaced on theilow'er tapered end of the shaft I2, properly meshed with the beveled drive 'gear '33 and locked in place with thelock-nut 35, as shown. The shaft '36 extends rearward to thepower source (not shown) whereby the impeller may be driven at any desired speed and in the desired direction of rotation The gear housing?! maybe filled with lubricant through the filler 'plug opening at (Fig. '1) and drained 'thl oli'gh'the plug opening '39. The lower bearing '30 receives itslubricant from the gear housing, while the upper bearing '2! is lubricated through the grease nipple '40 in the jam nut 28, or otherwise. I l I Because m'yirn'peller structure is designed to be driven at 'rerauvei highspeed'ajitvvill'be seen that the 'drivebrid olfjth shaft I2 maybe directlycoiipl'dtoj a suitable steam turbinefrotor sha'ftQOr other 'hi'gh's'peedheatengine and driven directly thereby "without 'gearsf'or other transmission devices and thi's'is the preferre typeor methodof'drive. i i It 'is essential that "th'e'entire impeller structure be constructed accurately andl rota't'e with a minimum or vibr 'upn at n all speeds. n w'ever, in order to neutralize any 'slight. unbalance, I provide for theii'se' offa fluid which is normally positioned "within the'lower internal portion of the nembfer't, toaeta an automaticvibration damper 'or' harmonic balancer. This fluid :may be a light oil and isfin'trodiiod tnr' iigil the hole 19 removing the nut and tliels crew 9 11s 2! A ter ki rr rfiuaeiity Qifi is p red. bri dott d lin v Fi 2. 1 zila d eryoi'the air-foil head I, below the'vacuum plate 3, by.'c'entrifugal action, thefluid position therein being indicated by the vertical dotted lines '42, when the impeller is rotating at top spel id.

Thus, f vibrationtends to develop, due to slight unbalance, it is instantly damped or neutralized.

"position orpoint The lower i c e ayu to. t Q1':m,i .1. d lev l i d e 'and outwardly throughout the internal periphdiameter, the

'tialliiies mafia provides lower portion of the impeller head and for this reason the fluid fill should be proportional to operating conditions or requirements.

The fan shown in Figs. 6, 7 and 8, is preferably 'oastof suitable material, while the parts i,

3 and 4 may be made up of suitable sheet material, although they may also be cast and machined to size. In the latter case, the seal shown at S -l6, (Fig. 2) betweenthe members I and a, wouldbe alteredfto suit requirements. In other words, the extreme ed'ge of member t would not be rolled overthe extreme edge of flange 9 assho'wn, but would be flat welded, as shown at Fig. 9, or otherwise secured to same, to effect a fluid tight joint. Theinternal bracing of the impeller may beof an'yd'esired design and character to obtain maximum strength and resistance to the developed stresses, without departing from the character and principle of the invention. ,7 7

Assume that the impeller'has been set up in the vertical position shown and-suitably connected to a source of power, "so that it maybe driven at any desired speed Within the centrifugal capacity of the impeller unit and that the fanemployed is of the straight vane type "shown in Eigsl, Zand 8. This fan, regardless of the direction of 'rotation, will displace air at -right angles to the axis, outwardly over the curved air-foil area of the impeller 'head,'as indicated by the curved arrow lines 43 and cenjtrifugal force, acting on the air in contact with the external curved surface of member "4, will displace air in the direction'indicat'ed by the curved arrow lines 44. i

I It isjwell known' that the greater the total "effectivearea of the vanes; of an air fan of unit I greater the'power required to drive it at a given speed and it is also wellknown that it is the velocity and "not the volumeof the air stream forced over an air-foil surface that develops the vacuum or negative pressure eifect.

Therefore, it is advantageous to employ a centrifugal air fan of maximum diameter and minimum total area of vanes, whereby the'driving power required' would be reduced to aminimum to'develop and maintain the highest possible vacuum value.

The air displaced radially :by .the'fan creates a partial vacuum, indicated by the-"verticallines 45,'immediately above or ahead of sam'eand'over its central "portion and also overt-the extreme outer curved :area of the, air-foil surfaceofmemher I, approximately as indicated;by-the vertical lines 46. The vacuumohamber t'l;injtheupper or forward end of the impeller head 1, is-in con nu u qm un c t hext nalv p um. ar itat db t e. v ri a 1 3 means of the slots or, parts l0, hence :the degree of vacuum within this 'ehe'ater isfalw a the sameas that over the area india tedbys aidfverroe-e. ma ma "effecgiven; dia eter idfjiittive vacuum area "for a;

pener 'li'ead; The *piirpiise of this internal vacuum is to create an inward pull onthe inner surface of the impeller head toward center whereby. to neutralize or counteract centrifugal force acting on the impeller mass. Any moisture condensing or otherwise entering the chamber 41 through the ports I would be discharged immediately through said ports by centrifugal forc i that the resultant vacuum and thrust factors per square inch of effective area, would also be of a relatively high order or value.

Now, assume that the impeller .is driven at, say

two or three hundred R. P. M., the velocity of the chamber 41 until, at the maXimumR. P. M.,

air stream 43 (at atmospheric pressure) would contact only the extreme outward portions of the fan vanes-as shown and a maximum vacuum or negative pressure value would be attained over an effective area equal to the flat cross-sectional area of the impeller head, resulting in a powerful vertical or horizontal thrust, according to the position of the impeller.

The high velocity and pressure effect of the air stream 44 adds to the thrust effort by virtue of the curved under surface of the member 4, at

or near its outer periphery and also prevents the formation of a vacuum effect at this point when the impeller is moving at maximum speed in either the vertical or horizontal direction. The

volume of this air stream is very low, since-it is developed by centrifugal action on the air in contact with the smooth surface of the member 4.

However, this volumemay be increased, if desired, by providing suitable fan vanes within the.

curved external area of the member 4, as shown by the dotted curved line 48 on one side of the drawings (Fig. 2). not be employed when the curved vane fan, shown in Figs. 6 and 7, is used, for the reason herein-;

after explained.

If the impeller is to be employed for vertical and forward horizontal night only, then the straight fan vanes shown may be used, but if the airship or. otherv craft involved is to be driven in a reverse as well as forward direction, then the curved fan vanes 5, Figs. 6 and 7, should be used, because when this fan (with vanes curved in the direction shown) is rotated clockwise, a centrifugal displacement of the air is achieved, as shown in Fig. 2, employing a straight vane fan, but when the curved vane fan is rotated in the opposite or anti-clockwise direction, it operates in a centripetal action to force air from its periphery toward its central area, thereby increasing the air pressure over this area and thus force the craft to move backward, or oppose its forward motion and bring it to a stop. This centripetal action will not be as powerfu1 as the centrifugal action because the effective area is very Such vanes, however, should air stream 44, (Fi 2) should be of minimum value, as it will oppose the centripetal action of the curved vane fan. I 5 h The required operating speed of this device, to

achieve maximum efficiency, may be very much higher than that of the conventional propeller audit is designed to operate at speeds up tofifteenthousand or more R. P. M., according to diameter. The maximum speed for any given diameter of impeller head is limited only by the ability of the structure to withstand the centrifugal stresses developed, hence it should be constructed of strong, light weight material. However, centrifugal force operates to increase the rigidity of the structure and, in the vertical position, gyroscopic force acts to stabilize the impeller and the craft on whichit is installed. It may be constructed in any size upto twelve ormore feet in diameter, providing it is properly and sufficiently braced internally and constructed of theproper materials. Its efficiency increases with diameter, even at. correspondingl reduced speeds. I, i

For instance, disregarding air slippage or losses, an impeller one foot in diameter, with aneffective area of 113 square inches and a fan eight inches in diameter, rotating at 15,000 RQP. M. would develop an indicated thrust of approximately 9'71 pounds, while an impeller three feet in diameter, with an effective area of slightly over one thousand square inches and a fan 24 inches in diameter, rotating at 5,000 R. P. M. would develop an indicated lift or thrustof approximately 8,746 pounds, while the velocity of .thus'eliminate the necessity of employing, the conventional wing structure, it may also be employed in any application where the conventional propeller or air screw is now used and with great- -er efficiency. It may also be advantageously employed on specially designed, high speed, light weight marine craft, instead of theconventional marine propeller. The circular rotary air-foil, with its developed centrifugal forces, prevents the formation of ice upon its surface underthe severest conditions and thus insures a maximumvacuum effect and operating eff ciency at all times.

It is practically noiseless in operation. Only a low pitched, humming notewould be audible within close range. For this reason, when employed with suitably designed air or marine craft and powdered with noiseless, high pressure gas turbines, directly coupled to each impeller, it would be invaluable, in the war program in many different ways. On an equivalent production basis, it would cost no more, if as much, as a modern controllable pitch air craft propeller, and when employed with suitably designed air craft, it would provide all the advantages of the helicopter type of craft, plus greater efficlency and load capacity per unit of power, whereby relatively large transport units may be constructedand operated with superior results.

What I claim is:

1. An impeller for aircraft, comprising a rotary air-foil, comprising a circular air-foil head having a central concave area, and having radiating fan blades projecting from the air-foil head, and

. much less andfor this reason the volume of the h vinga plurality or ports disposed circumferel'itiallydf the air-r011 neadand having 3 bell shaped member having its edge secured to-the edge of the airfoil head a vacuum plate mounted in'the air-foil head, and inea'ns f'or driving said members at relatively high speed.

2.;An impeller for aircraft, comprising a rotary airfoil having'a curved headhaving a concave 'central portion, and having projecting radiating fanblades mounted on the outersurface of "the air-foil head to effect centrifugal action and create a'vacuum'directly in front of the head, and

"a bellgsha'ped member having its outer annular edgeaiiixed'to the edge of the air-foi1=head,' and a vacuum plate in the air-foil head having its central portion spaced from the central portion of the air-foil head, and having its outer annular "edge affixed to the internal curved surface oi' the air-foil head, S and --means "to maintain -a vacuum between the aforesaid head and the vacuum plate "for the purpose of neutralizing the action of centrifugal'force acting onthe impeller m'ass.

3. An impeller for aircraft, comprising-a circular rotary airfoil having a curved head having-a "concave central portion, projectinglongitudinally curved fan blades mounted on the outer surface of the airfoil head to effect centrifugal action and create avacuum directly in front of the head, a "bell-shaped member having its outer annular edge affixed to the edge of the airfoil head, the airfoil head having spaced ports, and a vacuum .plate in the airfoilhead having its central portion spaced from the 'central portion of the airfoil head and its outer annular edge aiiixe'd to the internal curved surface of the airfoil head.

4. An impeller for airciafhcompiising a circularalrfo il head having a centra1 concave area, radiating'fan blades projecting from the air-foil head, a. plurality of ports disposed circumferentially of the air-foil head,-a bell-shaped "member having its edge secured to the edge of the air-foil head, means for driving said members at relatively high speed, and a circular vacuum plate 'mounted in the air-foil head, said plate having-a plurality of radially disposed ribs, the outer edge of said plate having a flange engaging the internalcurved'wall 'of the air-foil head just below the aforesaid ports in the air-foil head.

'5. An impeller for aircraft, comprising acircular air-foil head having a central concave area, radiating fan blades projecting from the air-foil head, a plurality of ports disposed circumferentially of the air-foil head,'a bell-shaped'me'mber having itsedge secured to the edge of the airfoil head, means fordrivingsaid members at relatively'high speed, anda circular vacu um plate mounted in the air-foil head, said plate having a plurality of radially disposed ribs, the outer edge of said plate having a flange engagingthe internal curved wall of the air-foil-head just belovv'the'aforesaid ports, and means for'mounting said plate in spaced relation to the centralxportion pfr'theair-roii hea'd.

6. Animpel'ler forairc'ra'ft, comprising :aeircular aid-foilheadhaving a central concave area, radiating fan bladestprojecting from the air-foil head, "a plurality of ports disposed circumferentially of 'the air-foil 'head, a bell-shaped member having its edge secured to the edge of the. air-foil head, means :for driving said members at rela- --tivelyhigh spe'ed, a circularva-cuum plate mount- :ed 'inthe air-foil head in s'pac'edrelation to said head, the outer edge of said plate engaging the internal curved wall "of "the air-'foilihead just below the aforesaid ports, a central shaft on which the air-foil head is :secured, means on said shaft spacing the air-foil head "and'the vacuum ,plate apart, and 'a bearing housing in which said shaft is mounted.

7. An i'm'peller for aircraft, "including a rotary air-foil havingla central concave area, and having radiating fan vanes, and having a plurality of ports in the air-foil head, and a bell-shaped I member having its outer annular edge secured to the edge of the air-foilheadand ports disposed circumfere'ntially of the air-foil head, wherebya developed vacuum and pressure eflect may be created, the vacuum being created over the outer surface of the air-foil head and the thrust being exerted against the bell-shaped member, substanjtially as-described and shown.

8. In combination with themechanism defined in claim-'7, said blades being smallest near the center-of the air-foil .head-and -gradually expanding in area toward the rim of said head, but not extending to'therim thereof, and a driven shaft on which said air-foil head "and bell-shaped member'and vacuum plateare rigidly mounted.

9. An impeller for aircraft, comprising a rotary air-foil, including a circular air-foil head having a central concave area, radiating 'fan blades ,pro-

, jecting from the'air-foil head, afplurality of ports .action viill throw the liquid upwardly and loutwardly to neutralize any unbalance due to the action of the fluid moving towardthe diametrically opposed "position or point of unbalance, and means for'drivin'g all ofsaid members at relatively highspeed.

HARLIE OQP-UTT. 

